1. Field of the Invention
This invention relates to stabilized aqueous solutions of a chemical (cisplatin).
2. Description of the Prior Art
The platinum compounds are a unique group of compounds in the antineoplastic group of agents. They were first noted to have an antibiotic effect by Rosenberg and his colleagues in 1965 and have since been found to be potent antitumor agents in animals..sup.1,2 FNT .sup.1 Rosenberg, B., VanCamp, L. and Krigas, T., Inhibition of cell division in Escherichia coli by electrolysis products from a platinum electrode. Nature (London) 205: 698-699, 1965. FNT .sup.2 Rosenberg, B., VanCamp, L., Trosko, J. E. and Mansour, V. H., Platinum compounds: A new class of potent antitumor agents. Nature (London) 222: 385-386, 1969.
Structurally they represent a complex formed by a central atom of platinum and surrounded by various arrangements of chlorine atoms or ammonia groups in either a cis or trans planar relationship. Two of the more commonly studied platinum compounds are diagrammed below: ##STR1##
As can be seen, the platinum compound, cis-platinum (II) diamminedichloride, selected for clinical trials by the National Cancer Institute has the chloride and amino groups only in the horizontal plane. The cis form of the diamminedichloride complex has been synthesized according to the following reaction:.sup.3 ##STR2## FNT .sup.3 Kauffman, G. B. in J. Kleinberg (Ed.), Inorganic Synthesis, McGraw-Hill Book Co., Inc. New York, 1963.
The National Cancer Institute has been conducting clinical trials in cancer chemotherapy of the chemical for which the United States Adopted Name (USAN) is now cisplatin. Certain information regarding its chemistry and its pharmaceutical formulation are given in the publication titled Clinical Brochure, CIS-PLATINUM (II) DIAMMINEDICHLORIDE (NSC-119875), H. Handelman et al., Investigational Drug Branch, Cancer Therapy Evaluation Program, Division of Cancer Treatment, National Cancer Institute (Revised, August, 1974), on pages 1-5 and 31-32. The last two pages of Handelman et al. concern the formulation of cisplatin supplied gratis by the N.C.I. to clinicians for their clinical evaluation in the chemotherapy of cancer and read as follows: